Free electron lasers (FELs) are useful for various applications, since they can provide intense radiation in various parts of the electromagnetic spectrum, such as X-rays. In a free electron laser, radiation is emitted by the interaction of an electron beam with an undulator. However, conventional free electron lasers tend to be large and complex systems, mainly driven by the complexities of the large-scale magnetic undulator typically employed.
Proposals have been made to provide an undulator suitable for use in a free electron laser using optical techniques. However, these approaches have not yet provided competitive performance relative to traditional FEL approaches.
Accordingly, it would be an advance in the art to provide improved X-ray sources via the interaction of an electron beam with an optical undulator.